Attachment-plug.



C... VETTER. l ATTACHMENT PLUG. APPLICATION. mso A Pn. 1o. |915,

Patented Apr. 1, 1919.

.v ...L 1.3.. l I" l m *TENT onirica.

CLARENCE A. VETTER, PITTSBURGH, ENNSYLVANIA.

Specification ot'Lette'rs Patent.

' rPaten-ted Apr. 1, 1919.

i -Appncationiedjaprn10,1915. seria1No.2o,42s.

to the conductor wires,rwhich relievesstrainl` on the binding screws,and, which. can be made at low cost and/is notliable to'v'getout oforder. .l l

Further objects ofthe invention are in part obvious and in part.4 willappear more in detail hereinafter.

The inventionl comprises the attachment plug hereinafter described andclaimed.

In the drawings. Figure l represents a side elevation of ,an attachmentplug embod `ving the invention; Fig. 2 isalongitudinal sectional viewthereof; Fig. 3 is a longitudinal section on the line 3'-3, `F ig. 2,looking in the direction of the: arrows; and F ig.I l is lan end view ofthe base looking directly at the binding screws. j

The plug shown in the ldrawings comprises two members, a basel and alcap 2, which are preferably madeA4 of porcelain, composition, fiber,hard rubber or any` other suitable non-conducting material.

.The base 1 has one end` rounded to enter the lamp socket to which theplug is to be attached. lts upper end is cut ofi' square and is alsohollowed out or recessed to provide two opposite side cavities, marked 3and l, separated by a thin longitudinal wall 5, which prevents shortcircuits between the plug terminals. and which wall connects the twotriangular solid side portions 6 at the upperI end of the plug. The basealso carries two current conducting members, marked 7 and 8respectively, which are formed of suitable conducting material, such asbrass or other` metal. These members are molded in the base l during themanufacturing thereof, and are preferably made of sheet or plate metalwith openings 9 therein to receive portions o't' the material of thebase to prevent said membersl from pulling outi endwise from the base.

One end of the conducting member 7 projects from the rounded end of thebase and is bent over 4flat at its center to form the end contact of theplug. The other end of said member extends into the cavity 3 and isthere provided with a binding screw 11 'for securing one of theconductor wires 12 thereto.

The other conducting member 8 terminates at one end within the body ofthe base 1. lts opposite end extends into the cavity l. where it isprovided with a binding screw 13 for the other conductor wire. Beyondthe binding screw member 8 is forked or bifurcated substantially inY-shape, as shoWn in Fig. 3, to form two arms or extensions 1l, vtheouter ends of which are bent over flat and lie in shallow grooves in theflat ends of the triangular portions G of the base 4andgform a portionof the circuit connections to the other contact of the plug.

The second contact ofthe plugis the usual hollow screw-threaded shell15, which surrounds the base and closes the cavities 3 and 4 and is madeof pressed metal with a portion of'said shell molded into the materialof the cap, so that the shell is in effect an integral part ofthe cap.As shown, the shell has an upwardly extending annular Wall 16terminating in anY outwardly eX- tending rim or flangel '16a embedded inthe cap so that it will not accidentally pull out. The annular rim neednot be continuous around the entire periphery and may be merely a seriesof ears or tongues struck or bent up from the end of the cap, as will bereadily understood. The cap is also provided With a central opening 17for the conducting cord or Wires and With an inner enlarged chamber 18to receive a knot in said wires for relieving the strain from thebinding screws. The wall of the shell 15 is also provided with aninwardly extending annular rib or bead 19 to coperate With a sha1# lowannular groove 20 in the base 1.

In assembling the plug the cap 2 is slipped over the end of theconducting wires which are then knotted and attached at their free endsto the binding screws 11 and 153. The cap 2 is then pushed up over thebase, the annular bead 19 being forced over the end of said base andinto the annular groove 20 thereof. The internal diameter of the bead 19is just a little smaller than the eX- ternal diameter of the base 1, sothat a little extra force is necessary to overcome the fric- -eiicientform of attachment plug.

tion and push the bead over the end of the base and into the annulargroove. The bead and groove form a swivel connection between the cap andbase, enabling the plug to be screwed into a socket without turning thebase, and also prevent accidental separation of the two members whentheplug is disconnected from the socket. Electrical connection betweenthe shell 15 and terminal 13 is provided by the arms or extensions 14 ofthe member 8, which lie near the periphery of the base 1, and when thecap 2 is screwed into a socket are forced tightly into engagement withan inwardly extending flange or wall 21 of the shell 15.

This plug is very simple, as it comprises only two parts and thereforeto a large degree prevents loss of the parts. It can also be made verycheaply and is a simple and It can be readily attached to the conductingwires without special tools or implements, relieves all strain of thewires on the binding screws, and can be readily manipulated by merelypulling the cap off from the base to expose the binding screws fordisconnection at any time.

What I claim is: v

1. An attachment plug comprising a base having a central end terminalmolded therein, a cap having a screw shell molded therein, a secondterminal member molded in the base and adapted to normally contact thescrew shell, binding screws on the terminal members, and means toholdtheV cap and base together.

2. An attachment plug comprising a base having a central end terminalmolded therein, a cap having a screw shell molded therein, a secondterminal member molded in the base and adapted to normally contact thescrew shell, binding screws in recesses in the base on the terminalmembers, and means to hold the cap and base together.

3. An attachment plug comprising a base having a central end terminalmolded therein, a cap having a screw shell molded there; in, a secondterminal member molded in the base and adapted to normally contact thescrew shell, binding screws on the terminal members, and means to holdthe cap and base together .in swiveling relation.

4l. An attachment plug, comprising a base having two current conductingmembers molded thereinto, one of said members torming an end contact,said base being provided with oppositely disposed cavities.saidconducting members having portions extending into said cavities, and 'acap connected to the base by an angular rib on the cap and a coperatinggroove in the base and carrying a shell Contact.

5. An attachment plug comprising a base having two terminal currentconducting members molded'therein, one of said members forming an'endcontact, oppositely disposed cavities in the base, extensions from thetwo terminal members into the two cavities respectively, binding screwson the extensions, and a cap carrying a screw shell adapted to slip overthe base and to electrically connect the screw shell and the terminalmember in the base not forming the end contact.

6. An attachment plug comprising a basel having a central terminalmember molded therein, said member having a projecting portion with a.binding screw thereon in a cavity in the base, a second terminal membermolded in the base and having a projecting portion with a binding screwthere-- on in another cavity in the base, an annular depression in thebase, and a cap carrying a screw shell adapted to t over the base andhaving an interior rib on the screw shell adapted to engage thedepression in the base to make electrical contact with the conductingmember therein and to hold the base'and cap in swiveling engagement.

7. An attachment plug comprising a cap carrying an integral screw shell,a base carrying an end contact molded therein, and a resilientlyinterlocking projection and depression between the base and screw shellproviding a swiveling engagement between the cap and base.

8. An attachment plug comprising a rotatably connected base and cap, acenter terminal contact member molded into the base, a second terminalmember molded into the base, a` screw shell molded into the cap, andmeans to electrically connect the screw shell to the second terminalmember.

9. An attachment plug, comprising a base having a central terminalcontact member molded therein, a cap having a threaded outer contactshell membermolded therein, and means to retain the cap and base inrotatable connection comprising a rib on one and an annular groove onthe other adapted to be engaged and disengaged by forcing lthe.rib intoand out of the groove.

ln testimony whereof I have hereunto set my hand.

CLARENCE A. VETTER.

lVitnesses: Y

F. C. KRAUs, H. S. LINDSAY. g

